Refactor SLP endpoint to remove address and utxo collections

[christroutner]

James Cramer informed us that new versions of SLPDB will have the address and utxo collections removed. James looked at our SLP route library and he determined that 4 endpoints rely on the address collection and none rely on the utxo collection.

The scope of this issue is to refactor the SLP route library to use alternative SLPDB queries.

Here is an example query that can retrieve an address balance by parsing all the utxos. This query will comply with the new changes.

[christroutner]

Added the discussion label to this Issue as it should be broken up into multiple small issues, one for each endpoint that needs to be updated.

[christroutner]

Testing notes from 1/15/2020:

• Git commit: 6de9d0efac3b89c95bccc8aa7cb48eee799819c7 from db-updates branch.
• Synced in: ~ 12.5 hrs on a Droplet with 8GB of memory and 32GB of swap
• Reached 95% memory usage during sync, but did not crash.
• Crashed after sync, but restarted and got back to the running state in less than 10 minutes

[SpendBCH]

Updated endpoints here: fc058b3

Based on query for balances by address and query for balances by tokenId

[jcramer]

By default, the response limit is 100. Depending on how you're using queries these in production consider adding "q.limit" to be something higher than 100 or do something for pagination of very large results lists.